What is the effect on gravity underwater?

[jonnythan]

Not to sound condescending, but this is all basic high school physics. There's nothing more complicated than that going on.

 

[redacted]

I think this is related to the similarities in the fluids an the slight difference in the S.G. of each. Eventually the blood will drain down.

If you are correct, hang up the corpse, put it in a pressurized vessel in air and lop off the top & bottom. Will the blood stay? No, the blood will run right out. It will not be slowed like it would immersed in water.

Pressure would have to be high enough to make the specific gravity of the air 1.00 in relation to water. I'm pretty sure it would not remain a gas but that's probably going to make me go looking for a physics book.

 

[redacted]

My, this thread has taken a gruseome turn... :11:

I caught a opossum in my raccoon trap last night but my wife say it is NOT going in the pool. :06:

 

[novadiver]

and this PHD info came from ? Because in my sourse info it states that THE HEART is a central pump. MEANING the body was designed to be in a possition to allow proper blood flow.( off gassing in this case) not up side down or horizontal.

 

[JimC]

Hypothesis: Blood does not rush to the lowest point while a body is submerged in water.

Procedure:
- Do prolonged headstand on land
- Evaluate 'head rush' effect
- Do prolonged headstand in water
- Evaluate 'head rush' effect

Results
Headstand on land produced head rush and headache feeling. Both things disappeared shortly after lying down.
Headstand in water produced short duration of vertigo and then become completely comfortable until mask leaked slightly and water began leaking into nose.

Conclusion:
The blood in your body does not have a tendency to be pulled to the lowest point in your body when underwater as it does on land.

 

[Rick Murchison]

Nice illustration. However, blood has a lower density than water, right? Especially with disolved nitrogen?

No, it's essentially the same (the actual density of blood is somewhere between fresh and salt water, but it's so close that the ziplock bag example would work well if there were blood in it and you submerged it in salt or fresh water)

Isn't this one of the arguments for horizontal ascents? Just curious.

No, the argument for horizontal ascents is to reduce the pressure differential between the deepest and shallowest part of your body - and therefore reduce the variability in the propensity for bubbling - and therefore make your body conform more closely to the decompression model you're using.
S

 

[Rick Murchison]

I understand this is your belief. I don't understand why you believe it. Have you seen any evidence to indicate this is the case? Simply repeating it doesn't make it so.

Take two bottles full of fresh, unclotted blood underwater (add a little heparin so it'll stay unclotted for you. Or, you can use water and food coloring - you'll get the same result) Turn one of them upside down. Take the tops off both of them. Watch what happens.
Report back with your findings.
S

 

[jonnythan]

Jim and Sphyrna, great analogies.

How about a condensed version of my last post: the *outward* force of the blood due to being vertical [having a 6 foot tall blood column] is perfectly balanced by the *inward* force of the increased water pressure at your feet vs your head when you're in water. There is *no* [significant] corresponding *inward* force when standing on land.

 

[novadiver]

Blood IS thicker than water, the buoancy of blood depends on what is DESOLVED in it AND at what depth it is. The body matabilises gas slower in the RESTING position, and the pressure difference between head and feet is scientific fact. by reversing this pressure you are disturbing the bodies NATURAL function and releasing the micro bubbles to become BIGGER on their way BACK to the heart.

I am the ICEHOLE that started the debate on TSS, and I have done my homework on the subject.

If someone can post SCIENTIFIC INFO proving this is wrong , from a reputable source , I'd listen .

But please stop pulling bogus phisics out and calling it fact.

 

[redacted]

Hypothesis: Blood does not rush to the lowest point while a body is submerged in water.

Procedure:
- Do prolonged headstand on land
- Evaluate 'head rush' effect
- Do prolonged headstand in water
- Evaluate 'head rush' effect

Results
Headstand on land produced head rush and headache feeling. Both things disappeared shortly after lying down.
Headstand in water produced short duration of vertigo and then become completely comfortable until mask leaked slightly and water began leaking into nose.

Conclusion:
The blood in your body does not have a tendency to be pulled to the lowest point in your body when underwater as it does on land.

Alternate Conclusion:
The body mechanisms which counteract the tendency for blood to pool in the lower extremities are designed to function at 1atm in a medium with a very low specific gravity.

May be time for a new mask.